這個基因編碼的蛋白質是三碘甲狀腺原氨酸的核激素受體。它是甲狀腺激素的幾種受體之一，已被證明介導甲狀腺激素的生物活性。小鼠的基因敲除研究表明，不同的受體雖然有一定程度的冗余，但可能介導甲狀腺激素的不同功能。已知該基因突變是導致廣泛性甲狀腺激素抵抗（gthr）的原因，這是一種以甲狀腺腫和高水平循環甲狀腺激素（t3-t4）為特征的綜合征，伴有正常或稍高的促甲狀腺激素（tsh）。已觀察到該基因中編碼相同蛋白質的幾個選擇性剪接轉錄變體。
The protein encoded by this gene is a nuclear hormone receptor for triiodothyronine. It is one of the several receptors for thyroid hormone, and has been shown to mediate the biological activities of thyroid hormone. Knockout studies in mice suggest that the different receptors, while having certain extent of redundancy, may mediate different functions of thyroid hormone. Mutations in this gene are known to be a cause of generalized thyroid hormone resistance (GTHR), a syndrome characterized by goiter and high levels of circulating thyroid hormone (T3-T4), with normal or slightly elevated thyroid stimulating hormone (TSH). Several alternatively spliced transcript variants encoding the same protein have been observed for this gene.